Despite everything that has been written about the brain, a potentially critical part of this vital organ has been overlooked--until now. The Other Brain examines the growing importance of glia, which make up approximately 85 percent of the cells in the brain, and the role they play in how the brain functions, malfunctions, and heals itself.

Long neglected as little more than cerebral packing material, glia (meaning "glue") are now known to regulate the flow of information between neurons and to repair the brain and spinal cord after injury and stroke. But scientists are also...